Effect of TaC on phase, microstructure and mechanical properties of Ti(C_0.7N_0.3)-based cermets

In order to prepare Ti(C_0.7N_0.3)-based cermets with high hardness and high toughness, Ti(C_0.7N_0.3)-WC-Mo₂C-VC-AlN-Ni/Co cermets containing TaC were prepared by vacuum pressureless sintering at 1600℃. The effects of different TaC content (0wt%, 5wt%, 10wt%, 15wt%) on the phase, microstructure and mechanical properties of cermets were investigated. The results show that with the increase of TaC content, the main peak of Ti(C_0.7N_0.3) (200) gradually shifts to a lower angle, the thickness of rim phase increase gradually and the Vickers hardness and fracture toughness of cermet firstly increased and then decreased. When 10wt% TaC is added, the core phase size of cermets is refined with the smallest, and the rim phase is more complete and uniform, leading to the maximum Vickers hardness ((17.79±0.15) GPa) and fracture toughness ((10.20±0.39) MPa·m^1/2) of cermet.